#include <iostream>

using namespace std;

class Shape{
protected:
    int width;
    int height;

public:
    Shape(int a = 0 , int b = 0):width(a),height(b){

    }
    int area()const{
        cout << "parent class";
        return 0;
    }

};
class Triangle:public Shape{
public:
    Triangle(int a = 0 , int b = 0): Shape(a,b){
        
    }
    int area()const{
        return width * height*2;
    }
};

int main(){
    return 0;
}